This invention relates to an inertia reel; more particularly to a ballistic powered inertia reel; and most particularly to a ballistic powered inertia reel including a locking rod to prevent unwinding of the webbing during an emergency.
A wide variety of vehicles use passive-safety devices such as restraints and harnesses. These systems are especially important for fast moving vehicles where they must be capable of fast actuation in order to prevent or lessen the severity of potential undesirable events. These fast moving vehicles can subject the occupants to dangerous forces generated by rapid accelerations/decelerations during unexpected, undesirable events, such as a violent maneuver or a crash. These accelerations/decelerations can lead to large displacements of the occupant's body, which can result in the occupant's body or head contacting structures or objects within the vehicle. This can result in serious injuries or possibly death. Specially designed seats and restraint systems are typically used to restrain the occupant; however, excessive body displacement can still occur during the undesirable events due to the wide range of human body types and sizes.
Restraint systems include inertia reels that are designed to allow movement of the body during normal operation of the vehicle—such as reaching with the arms and turning of the torso while also being designed to lock (preclude webbing payout from the housing) when large accelerations or decelerations are detected. This minimizes the displacement of the seated occupant's body to mitigate the potential for injury. Furthermore, the seated occupant is sometimes out of position or engaged in reaching or turning motions during the onset of an undesirable event. For certain vehicles, such as aircraft which are equipped with occupant ejector seats, these restraint systems may further include rewind mechanics to retract excess payout of the webbing prior to or during initiation of the seat's ejection. In this manner, the occupant's head and torso are secured to the seat before experiencing the violent forces of the ejection where a pilot may experience forces upwards of 20 Gs.
Some inertia reels for use within restraint systems, however, suffer from unwanted payout of the webbing during or immediately following a seat ejection. This may occur when the rewind mechanics have retracted the webbing payout but the webbing reel lock mechanism has failed to lock against unwinding. This unwinding may allow for unwanted and uncontrolled movement of the pilot resulting in pilot injury or death. Furthermore, some ballistic powered inertia reels cannot be unlocked following an ejection to allow the webbing to unwind or allow the pilot to egress the ejection seat. This can be detrimental in instances where a pilot must quickly leave the area.